250.64(b) protection from physical damage

[erodriguez]

I have a question about using schedule 40 vs. schedule 80 for protection of the GEC (2002 NEC 250.64b).

I can?t find anything in 2002 NEC that distinguishes sch. 40 from sch. 80 for protection of the GEC. All it states in 250.64(b) is ?Rigid Nonmetallic Conduit?.

230.50 Changed from ?rigid nonmetallic conduit? in 99 NEC to ?Sch 80 rigid nonmetallic conduit? in 02 NEC.

I don't have a 2005 handy.

erodriguez

 

[hurk27]

Re: 250.64(b) protection from physical damage

There is no place where schedule 40 is allowed to be used for protection where subject to physical damage in the NEC. From what I was told it is from UL test done on schedule 40 and it didn't preform very well in some crush test done.

Infact even in the "99" NEC only schedule 80 was allowed to be used for protection where subject to physical damage. If not subject to physical damage, then schedule 40 all the way.

 

[augie47]

Re: 250.64(b) protection from physical damage

The key is possibly the UL grren book listing (DZYR) which states Sch 40 is only listed where not subject to physical damage. Sch 80 is listed where it may be exposed to physical damage.